March 13, 2006Travis Rector of the National Optical Astronomy Observatory (NOAO) and Tim Abbott of the Cerro Tololo Inter-American Observatory (CTIO) imaged cometary globule CG4 using the 157-inch (4 meter) Victor M. Blanco Telescope at CTIO about 50 miles (80 kilometers) east of La Serna, Chile. The pair used a 64-megapixel Mosaic imaging camera and blue, green, near-infrared, and hydrogen-alpha filters to expose the image.

A cometary globule is a glob of gas and dust shaped like a comet but lacking the solid, icy nucleus of an actual comet. Such nebulae are small, isolated star-forming regions within the Milky Way. The CG4 nebula contains enough gas and dust to form several stars about the size of the Sun.

CG4 lies about 1,300 light-years away in the constellation Puppis the Stern. The nebula's head is about 1.5 light-years in diameter, and its tail is some 8 light-years long. Electrically charged hydrogen from nearby stars causes CG4's faint red glow. Star formation depletes gas and dust from the nebula and causes its head to appear sunken.